The described male has a dark brown abdomen scattered with yellowish-white spots.
In the described female, the front of the abdomen is dark brown with yellowish spots, while the rear is mostly yellowish white. The legs have light brown areas and darker rings.
Eriauchenus lukemacaulayi occurs not only near the forest floor but also in litter held above it. Females were found in litter at Pandanus leaf bases about 1.8 metres above ground. Another female and an eggcase were collected inside a log leaning against a tree, about 45 centimetres above ground. Large leaf bases and fallen wood provide small refuges at different heights.
These specimens were collected in Andringitra National Park in January 2009 and used in the 2018 description. The two females from Pandanus leaf bases and the female collected with an eggcase have separate voucher records. Another female was collected beneath a dead log at 1,580 metres elevation. Detailed records of height and substrate reveal several small-scale settings within the same rainforest.
An extinction-risk assessment has not been added yet.
At Andringitra, where this spider was collected, FAPBM identifies deliberately set fires, selective tree cutting and fuelwood collection among conservation pressures. The fund describes collaborative management in which local communities participate through park and protected-area support committees, and states that its support for the park began in 2007. These are regional conservation arrangements.